Need help dating Wrangler cuffed bell bottoms made in Canada

I have searched everywhere for info on these Wrangler cuffed bell bottom jeans/trousers but I can't seem to find anything. I hope you can help!

Made in Canada

Fabric
50% polyester
50% cotton

Zipper
Lightning Zip (Ontario, Canada)

 

I have found similar pants online listed as 60s or 70s deadstock, but all were made in the USA, and all created with 100% cotton, cotton-rayon or corduroy fabric.

 

The CA number on the care tag indicates no earlier than December 1972, which is when the system came into existence. The coloured care tag symbols are too well-worn to be legible in the photo but that system came into use in Canada in May 1970. A clue is temperature: if the temperatures are in Fahrenheit, the jeans are from no later than early 1980: we switched to Celsius in December 1979 (then you have to add a bit of time because clothing was made 6 months in advance of sale). If in Celsius, 1980 to 2003 (we abandoned the colour care system then to conform to international standards).

 

I know I am a year late to the convo but I am trying to date a similar pair.

I cannot find a source that says Canada switched to Celsius in 1979, all of my sources say April 1 1975. Could you point me in the direction of your source for that info? My pair have a blue bell logo on them still as well, which made me second guess that they are from the 1980s, but they do list temperature in C.

 

That is a very useful info! When do you say Canada abandoned the color system, in 1980?